This invention relates to a ground working implement of the type including a rotatable body which has a plurality of tines mounted on the body for rotation therewith so that the tines can work the soil as the element is drawn over the ground. Devices of this type are often known as active harrows.
A conventional harrow includes a plurality of spring tines each of which is formed from spring steel with a lower tine portion and an upper coil portion attached to a fixed rod. As the harrow is drawn across the ground, the lower tine portion engages the ground and works the ground due to the flexible movement of the tine caused by the upper coil portion.
Harrows of this type have disadvantages firstly that the working of the soil is relatively limited. Secondly, the harrow has significant difficulty working in conditions where there is a collection of straw or other plant material, known as trash, on top of or in the upper layer of the soil. This plant material will collect around the harrow tines leading to a raking action and to an unacceptable collection of the plant material.
In current proposals for reduced till or no till farming practices, significantly greater amount of straw and other plant material is left as trash in the upper surface of the soil and therefore modern equipment must be designed in a manner to accommodate this material while providing a satisfactory or preferably increased level of harrowing action.
Various proposals have been made for rotating type harrows or active harrows in similar ground working implement in which there is a body rotatable generally about an axis parallel to the ground with the body carrying a plurality of harrow tines extending outwardly from the surface for engaging the ground. Devices of this type are achieving some success but up until now have had significant difficulty in accommodating high levels of trash and in providing the required of level of harrowing action.